The paper “Color Harmonization” from Daniel Cohen-Or and al., published July 2006 by Association for Computing Machinery, describes a method for harmonizing colors of an original image in order to obtain an harmonized image, the method comprising:                for each of a plurality of color harmonic schemes, computing a color comparison result from colors of the original image and colors of the current color harmonic scheme,        selecting the harmonized image obtained with the color harmonic scheme minimizing the color comparison result.        
In the paper, the color comparison result (F) is given by:
  F  =            ∑      p        ⁢                  ⁢                                                H            ⁡                          (              p              )                                -                      E            ⁡                          (                              m                ,                ∝                            )                                                  ·              S        ⁡                  (          p          )                    
where p is a pixel, H(p) and S(p) respectively denote the hue and saturation value of the pixel p, ∥ ∥ refers to the arc-length distance on the hue wheel, E(m,α) is the sector edge hue of the harmonic scheme (m,α) that is closest to the hue value of the pixel p.
The method described in this paper has the disadvantage of producing an harmonized image which is not always faithful with respect to the composition of the original image.